ABSTRACT
OBJECTIVE: The aim of this study was to evaluate the influence of root canal curvature (curved and straight root canals), prepared using reciprocating and rotary files, on wall cleanliness during root canal treatments. METHODS: Thirty curved and 30 straight human root canals were prepared using ProTaper (Dentsply), Pro- Taper Next (Dentsply) and Reciproc files (Dentsply) (n=20/group). The roots were split longitudinally and observed using a scanning electron microscope. Six micrographs were obtained at 1, 3 and 5 mm from the working length (WL). Two blinded observers scored the amount of debris. Mean debris scores were compared using a non-parametric the Mann-Whitney U test or Kruskal-Wallis test, and a Bonferroni correction was used for multiple comparisons. RESULTS: Considering all the shaping systems together, the debris scores were lower in curved root canals (P<0.05). Reciproc and ProTaper Next performed better than ProTaper in straight canals (P<0.05). No difference was found between ProTaper Next and Reciproc regardless of the canal curvature or distance from the WL. Considering all the shaping systems together, cleanliness increased when pulling away from the WL. CONCLUSION: The anatomical configuration of the root canal influences the quality of cleaning by shaping instruments regardless of the instrument kinematics during endodontic procedures. In every circumstance, the last millimetres of the apical third remain the most difficult area to clean.
ABSTRACT
Forty two single-rooted teeth, prepared with the Mtwo system, were divided into three groups based on the filling method: control, "Single-cone" (n = 20) (Mtwo gutta-percha single-cone tapered according to the diameter, length and conicity of the preparation) and "Combined system" (n = 20) (BeeFill 2in1). The parameters studied were apical leakage, gutta-percha adjustment, number of voids, presence/absence of sealer, root canal morphology, residual fragments, and filling of lateral/accessory canals. A dye penetration test was carried out (methylene blue). The teeth were embedded in resin, cut transversally and observed. The data were analyzed with non-parametric Mann-Whitney and Spearman tests. Comparative tests between the two groups showed that the "Combined system" was superior in terms of apical leakage (P < 0.01), gutta-percha adjustment (P < 0.05) and filling of lateral/accessory canals (P < 0.05). There were statistically significant correlations between master cone adjustment and root canal morphology (P < 0.01) in the "Single-cone" group. In the "Combined system" group, a relation was observed between the voids and root canal morphology (P < 0.05) and between voids and residual fragments (P < 0.05). The quality of obturation with warm gutta-percha was better than that of the tapered single-cone technique. Root canal morphology influences gutta-percha adjustment. Residual fragments on the root canal reduce sealing ability.